Just finished installing a set of Bosch III's (pictures and small write-up within)
07-29-2010, 09:29 PM
#21
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Great write-up and the pictures really added to the descriptions. My #24 lb Bosch IIIs are grey instead of Orange, and have a small clear/white plastic disc at the bottom of the injector.
When I lifted off the fuel rail I noticed gas varnish in the seats of 4 of the fuel rails. I used a very light wire brush cup with a dremel tool (on lowest speed and very light pressure) to remove the varnish. Brake cleaner, wd-40, etc wouldn't touch it.
Got the new injectors in, reconnected the battery, and let idle for 15 minutes, per instructions.
Over the past 2 days I have noticed three big improvements.
1. The long crank time (4 - 8 seconds) after sitting for an hour issue is gone. It now starts right up.
2. The stumble at idle, while in Drive, went away. It would stumble once every few seconds hard enough to feel like somebody hit the car with another car.
3. Gas mileage has gone up. I fiddle with the avg mpg computer a lot and on some runs where I used to get 16 - 17 I now get 18-19. Time will tell if this continues to be true.
Thanks to Jon at FIC. I emailed about 9:00 PM one evening with a question about which injectors to order and got an email response a couple of hours later.
Jon then called the next day to see if I had any more questions, and I placed the order over the phone. He must have sent them out the same day because I got them 2 days later via US Mail.
I also called his shop the day of installation with a question about the plastic disc on the injector tip and the guy who answered the phone also knew the answer to my question. It was a 45 second call and I had what I needed. Rare!!!
So, great experience with Jon and FIC, injectors work well. Old injectors all resistance tested at 16.0, so that was no help, but they were definitely leaking into the cylinders.
My 96 has 119k, and definitely made a difference.
Mike
When I lifted off the fuel rail I noticed gas varnish in the seats of 4 of the fuel rails. I used a very light wire brush cup with a dremel tool (on lowest speed and very light pressure) to remove the varnish. Brake cleaner, wd-40, etc wouldn't touch it.
Got the new injectors in, reconnected the battery, and let idle for 15 minutes, per instructions.
Over the past 2 days I have noticed three big improvements.
1. The long crank time (4 - 8 seconds) after sitting for an hour issue is gone. It now starts right up.
2. The stumble at idle, while in Drive, went away. It would stumble once every few seconds hard enough to feel like somebody hit the car with another car.
3. Gas mileage has gone up. I fiddle with the avg mpg computer a lot and on some runs where I used to get 16 - 17 I now get 18-19. Time will tell if this continues to be true.
Thanks to Jon at FIC. I emailed about 9:00 PM one evening with a question about which injectors to order and got an email response a couple of hours later.
Jon then called the next day to see if I had any more questions, and I placed the order over the phone. He must have sent them out the same day because I got them 2 days later via US Mail.
I also called his shop the day of installation with a question about the plastic disc on the injector tip and the guy who answered the phone also knew the answer to my question. It was a 45 second call and I had what I needed. Rare!!!
So, great experience with Jon and FIC, injectors work well. Old injectors all resistance tested at 16.0, so that was no help, but they were definitely leaking into the cylinders.
My 96 has 119k, and definitely made a difference.
Mike
07-30-2010, 01:48 AM
#22
good write-up - 
07-30-2010, 08:30 AM
#23
Thanks for taking the time to do a writeup. Somewhere down the road I'll get to replacing my injectors and I continue to hear nothing but good things about FIC.
I can't say my factory injectors with 108k miles are getting tired but they are all I know. The idle is the slightest bit lumpy and it revs fairly smooth (better since I've swapped in RRs) - so it's not new car smooth, but for a 16 year old sports car I have no complaints. My gas mileage is nothing short of awful but I can't blame the injectors, they are only obeying my will since this car is my toy and my right foot gets the better of me everytime I'm behind the wheel.
I can't say my factory injectors with 108k miles are getting tired but they are all I know. The idle is the slightest bit lumpy and it revs fairly smooth (better since I've swapped in RRs) - so it's not new car smooth, but for a 16 year old sports car I have no complaints. My gas mileage is nothing short of awful but I can't blame the injectors, they are only obeying my will since this car is my toy and my right foot gets the better of me everytime I'm behind the wheel.
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Jeff Fro (07-19-2023)
07-30-2010, 10:12 AM
#24
Drifting
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I have to agree that this is a great write up and with plenty of photos. You make guys like me who do not wrench their own cars feel like they can do it, with just a little patience and the right tools. I was shocked to see that you had the original fuel filter in there for so long and no one prior to you has ever changed it. I think I will tackle this job after my valve stem seal replacement. Thank you.
I 've had mine in now for over a year with NO issues.
07-30-2010, 12:59 PM
#26
Team Owner
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Co-winner 2020 C4 of the Year - Modified
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St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20
Great thread and info. The OEM fuel filter...I had that issue on both of my Vettes.
Link this thread to socalman's thread
here:
http://forums.corvetteforum.com/c4-g...post1574855687
Link this thread to socalman's thread
here:
http://forums.corvetteforum.com/c4-g...post1574855687
08-25-2010, 09:00 PM
#27
Hello:
You might consider the following if you have a C4 Convertible. The "Verts" have that special cross member (X) that will get in the way of replacing the fuel filter. This turns a relatively easy job into a nightmare unless you have the right tools
.
You will need a 16 mm crow foot and various (3/8) extersions to do the job. Also, you will have to unhook the two fuel lines from under the car (one to the filter and the return line) in order to have access to the 10 mm sheet metal screw that holds down the fuel filter retaining clamp. One of the lines lays right over the screw head and is just about impossible to get off without removing both lines. To make matters worse, the GM engineers put a rubber fuel line spacer that in impossible to reach (until you pull it through the engine). This spacer will hold the lower fuel line over the 10 mm screw that holds the fuel filter clamp secure to the frame. After I installed the new filter, I did not replace the rubber fuel line spacer so I could lift one fuel line out of the way of the 10 mm screw (next time I replace the fuel filter). If you are concerned about this, you might consider having to go through the right front wheel well and seeing if you can connect this spacer this way.
The fuel injectors went in as described above. Not all of the injector hold down clamps need to be removed with a small screwdriver. About half will slide off the rail after removing the old injector.
Please observe all safety items as listed above. When I started the car up, for the first time after replacing injectors and filter, I had my wife standing by with a fire extinguisher (just in case).
Take your time doing this work. I also found that jacking the car up and using 4 jackstands (I use 4 Rinos) makes it somewhat less painful when working on replacing the fuel filter and injectors.
Regards,
Ed Ward, Jr.
downnlock@aol.com
You might consider the following if you have a C4 Convertible. The "Verts" have that special cross member (X) that will get in the way of replacing the fuel filter. This turns a relatively easy job into a nightmare unless you have the right tools
. You will need a 16 mm crow foot and various (3/8) extersions to do the job. Also, you will have to unhook the two fuel lines from under the car (one to the filter and the return line) in order to have access to the 10 mm sheet metal screw that holds down the fuel filter retaining clamp. One of the lines lays right over the screw head and is just about impossible to get off without removing both lines. To make matters worse, the GM engineers put a rubber fuel line spacer that in impossible to reach (until you pull it through the engine). This spacer will hold the lower fuel line over the 10 mm screw that holds the fuel filter clamp secure to the frame. After I installed the new filter, I did not replace the rubber fuel line spacer so I could lift one fuel line out of the way of the 10 mm screw (next time I replace the fuel filter). If you are concerned about this, you might consider having to go through the right front wheel well and seeing if you can connect this spacer this way.
The fuel injectors went in as described above. Not all of the injector hold down clamps need to be removed with a small screwdriver. About half will slide off the rail after removing the old injector.
Please observe all safety items as listed above. When I started the car up, for the first time after replacing injectors and filter, I had my wife standing by with a fire extinguisher (just in case).
Take your time doing this work. I also found that jacking the car up and using 4 jackstands (I use 4 Rinos) makes it somewhat less painful when working on replacing the fuel filter and injectors.
Regards,
Ed Ward, Jr.
downnlock@aol.com
08-25-2010, 09:48 PM
#28
Safety Car
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St. Jude Donor '10
Great thread and info. The OEM fuel filter...I had that issue on both of my Vettes.
Link this thread to socalman's thread
here:
http://forums.corvetteforum.com/c4-g...post1574855687
Link this thread to socalman's thread
here:
http://forums.corvetteforum.com/c4-g...post1574855687
08-25-2010, 10:31 PM
#29
Drifting
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St. Jude Donor '10
Hello:
You might consider the following if you have a C4 Convertible. The "Verts" have that special cross member (X) that will get in the way of replacing the fuel filter. This turns a relatively easy job into a nightmare unless you have the right tools.
You will need a 16 mm crow foot and various (3/8) extersions to do the job. Also, you will have to unhook the two fuel lines from under the car (one to the filter and the return line) in order to have access to the 10 mm sheet metal screw that holds down the fuel filter retaining clamp. One of the lines lays right over the screw head and is just about impossible to get off without removing both lines. To make matters worse, the GM engineers put a rubber fuel line spacer that in impossible to reach (until you pull it through the engine). This spacer will hold the lower fuel line over the 10 mm screw that holds the fuel filter clamp secure to the frame. After I installed the new filter, I did not replace the rubber fuel line spacer so I could lift one fuel line out of the way of the 10 mm screw (next time I replace the fuel filter). If you are concerned about this, you might consider having to go through the right front wheel well and seeing if you can connect this spacer this way.
The fuel injectors went in as described above. Not all of the injector hold down clamps need to be removed with a small screwdriver. About half will slide off the rail after removing the old injector.
Please observe all safety items as listed above. When I started the car up, for the first time after replacing injectors and filter, I had my wife standing by with a fire extinguisher (just in case).
Take your time doing this work. I also found that jacking the car up and using 4 jackstands (I use 4 Rinos) makes it somewhat less painful when working on replacing the fuel filter and injectors.
Regards,
Ed Ward, Jr.
downnlock@aol.com
You might consider the following if you have a C4 Convertible. The "Verts" have that special cross member (X) that will get in the way of replacing the fuel filter. This turns a relatively easy job into a nightmare unless you have the right tools
. You will need a 16 mm crow foot and various (3/8) extersions to do the job. Also, you will have to unhook the two fuel lines from under the car (one to the filter and the return line) in order to have access to the 10 mm sheet metal screw that holds down the fuel filter retaining clamp. One of the lines lays right over the screw head and is just about impossible to get off without removing both lines. To make matters worse, the GM engineers put a rubber fuel line spacer that in impossible to reach (until you pull it through the engine). This spacer will hold the lower fuel line over the 10 mm screw that holds the fuel filter clamp secure to the frame. After I installed the new filter, I did not replace the rubber fuel line spacer so I could lift one fuel line out of the way of the 10 mm screw (next time I replace the fuel filter). If you are concerned about this, you might consider having to go through the right front wheel well and seeing if you can connect this spacer this way.
The fuel injectors went in as described above. Not all of the injector hold down clamps need to be removed with a small screwdriver. About half will slide off the rail after removing the old injector.
Please observe all safety items as listed above. When I started the car up, for the first time after replacing injectors and filter, I had my wife standing by with a fire extinguisher (just in case).
Take your time doing this work. I also found that jacking the car up and using 4 jackstands (I use 4 Rinos) makes it somewhat less painful when working on replacing the fuel filter and injectors.
Regards,
Ed Ward, Jr.
downnlock@aol.com
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Jeff Fro (07-06-2023)
08-26-2010, 09:11 PM
#32
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St. Jude Donor '10
The Haynes manual says to use engine oil to lubricate both the top and bottom o-rings of the fuel injector prior to installation in the fuel rail and intake.
06-20-2011, 08:21 PM
#33
Advanced
Finally installed Bosch III
LT1*C4
I had this thread (is that what it's called) on my desk top for over a year. Which means my 92 C4 was sitting in my garage not running properly and I'm thinking it's something really expensive to fix. I finally ordered the FIC Bosch III. On Fathers Day I decided that I will attempt to do this myself. I brought my laptop out set it nearby. I pulled off the the Fuel Rail Covers and then I could not figure out how to pull clips off top of Injectors I didn't want to break anything. So here I am sweating and nervous, so what do I do. I called Jon (FIC) on Fathers Day!! I did get them off and began following your directions. They where perfect. I put everything back went for a spin and car died. Battery quit. As I was pushing car that's when Jon called me back. I was taken aback. What a guy. Log story short my cables weren't tight. (Like my head). If anyone isn't sure about this project If I can do it you can do it. I'll repeat the Pics and Description are flawless. I could go on. I'm just so excited my ride is back. 
On those clips, you can just push the clips inward and actually just lift it of the Injector.
I had this thread (is that what it's called) on my desk top for over a year. Which means my 92 C4 was sitting in my garage not running properly and I'm thinking it's something really expensive to fix. I finally ordered the FIC Bosch III. On Fathers Day I decided that I will attempt to do this myself. I brought my laptop out set it nearby. I pulled off the the Fuel Rail Covers and then I could not figure out how to pull clips off top of Injectors I didn't want to break anything. So here I am sweating and nervous, so what do I do. I called Jon (FIC) on Fathers Day!! I did get them off and began following your directions. They where perfect.
I put everything back went for a spin and car died. Battery quit. As I was pushing car that's when Jon called me back. I was taken aback. What a guy. Log story short my cables weren't tight. (Like my head). If anyone isn't sure about this project If I can do it you can do it. I'll repeat the Pics and Description are flawless. I could go on. I'm just so excited my ride is back. On those clips, you can just push the clips inward and actually just lift it of the Injector.
06-20-2011, 08:45 PM
#34
Racer
Thread Starter
I'm happy to hear this post helped you out. Like I always say, if even just one single person is able to take any info/help/new ideas from one of my threads, it's worth it for me to take the time to post. 
I know that whenever I need information on something I'm not too clear on when I'm working on my car, it's always nice to find a thread in which somebody took the time to photograph and document the work they've done, so I can learn from them.
I just like to do my part to try and make this forum as helpful to others as it's been to me.
I know that whenever I need information on something I'm not too clear on when I'm working on my car, it's always nice to find a thread in which somebody took the time to photograph and document the work they've done, so I can learn from them.
I just like to do my part to try and make this forum as helpful to others as it's been to me.
Last edited by LT1*C4; 06-20-2011 at 08:52 PM.
07-27-2011, 05:02 AM
#37
SUPER THREAD - nice write-up and pics! i pretty much followed the OP's instructions on the injectors, and the replacement on my 96 LT1 went as smooth as silk. with the new boschIII's, a definite improvement - my leaking injector(s)starting issue are completely gone, and my seat-of-the-pants meter indicates the car just runs and feels better. i did replace the fuel filter at the same time - seems like there was no way in hell the filter was coming up through the engine bay, so i disconnected the line from the fuel rail, and lowered it slightly to gain access to the downstream or engine side fittings, and replaced the filter from below. the 10mm clamp bolt and the rubber spacer block didn't pose any issues in removing or replacing them. seems like the injectors and filter took about 2 hours. i rate the OP's thread at 5 stars, and !!! ...and a big thanks to Jon @ FIC for the sales and service!!!
!!! ...and a big thanks to Jon @ FIC for the sales and service!!!
07-30-2011, 10:17 PM
#38
Advanced
I also feel a difference with the Bosch III. Smoother response. My fuel filter was changed by the mechanic I use on my other vehicles before I realized the injectors where my issue. I looked at it and really didn't want to jack car up and tackle that. (no guts)
LTI*C4 deserves a lot of credit for that write up with pics and description.
Jon at FIC is the best I'd recommend him anytime. for both you guy's.
Never Forget
LTI*C4 deserves a lot of credit for that write up with pics and description.
Jon at FIC is the best I'd recommend him anytime.
for both you guy's.Never Forget
08-07-2011, 05:58 PM
#39
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Good write up!
Yes, very nice write-up indeed! The only problem is that I found this forum AFTER I bought my Accel 24lb'ers for my '91 coupé. It was still a little less than $300 for the set which is still a whole lot better than the $200 each my dealer wanted for the OEM injectors. I mean I know GM is in trouble, but c'mon... I don't think I should have to pay off their debt to the government all by myself!
If those Accels ever give up the ghost, I know where my next set of injectors will come from! And with all due respect to Jon, I hope its not for a while!
If those Accels ever give up the ghost, I know where my next set of injectors will come from! And with all due respect to Jon, I hope its not for a while!
08-07-2011, 08:02 PM
#40
Burning Brakes
Nice write-up and documentation. Jon is certainly the one to go to. I have a '93 that had new B III's when I got the car and had low mpg and lots of black smoke from being overfueled. They came from FIC and so gave Jon a call. He knew exactly what was wrong and sent out a new set. The impednice or something was different. What a big improvement. Now mine are not orange like yours are in the pictures and mine have 5 nozzle holes. 4 and 1 in the center. I also have some Bosch 4's I bought and tried and went back to the 3's. They are a little shorter and Jon olso had to make me some longer leads to plug in.